<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .a{
            width:200px;
            height:200px;
            background-color: aquamarine;
        }
        .b{
            background-color: bisque;
            margin-left:100px;
            width:50px;
            height: 100px;
            float:left;
        }
        .c{
            background-color: brown;
            width:50px;
            float:left;
        }
        .d{
            background-color: black;
            width:50px;
            float:left;
        }

    </style>
</head>
<body>
    <div class="a">
        <div class="b"> 1</div>
        <div calss="c">2</div>
        <div class="d">3</div>
    </div>
</body>
</html>